Procedure and mechanism for the automatic control of a grinding mill roller carriage equipped with a regulated product feed

In an improved system for use in a grinding mill for automatically controlling an operating condition controllable between first and second states, said system including position adjustable regulating means for regulating the operating condition;

• a fluid operated servomechanism operatively connected to said regulating means for adjusting its position and having an inlet and outlet;
• sensing means responsive to the operating condition for positioning an indicating portion of said sensing means in dependence upon said operating condition;
• valve means interposed between said servomechanism and a source of compressed fluid for controlling the supply of fluid thereto, said valve means including actuator means operatively connected to said indicating portion and responsive to the position thereof for moving between a first position and a second position as said operating condition varies between said first and second states;
• valve inlet means for connection to said source, and a valve outlet connected to said servomechanism inlet;
• the improvement comprising:
• said valve means having means responsive to the first position of said actuator means for producing a first operational mode wherein said valve inlet is blocked and said valve outlet is vented, means responsive to a position of said actuator intermediate said first and second positions for producing a second operational mode wherein both said valve inlet and outlet are blocked, and means responsive to the second position of said actuator for producing a third mode of operation wherein said valve inlet and outlet are connected with each other;
• and
• means for mechanically coupling said valve means to the regulating means so that a change of the regulating means position causes a corresponding movement of the valve relative to said indicating portion in a direction tending to urge said actuator to said intermediate position.